One project involving LandTrendr focuses on national parks in the western United States. A key piece of the work is to engage national park service interpreters in using change detection information to tell the story of their park. This section is designed to introduce interpreters to LandTrendr. We feel that the LandTrendr products may allow interpreters to:
First, we examine Landsat satellite images from 1984 to present, building a stack of information for the same place over many years. Here we show an example from Yosemite National Park.
Rather than inferring change on a landscape from the differences in two satellite images at a time, we examine a time-series of as many as 25 satellite images at once which enables identifying distinct deviations from a stable spectral trajectory.
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These satellite images create opportunities for seeing the earth in a wholly dynamic new way such as through a sequence of images where 25 years passes in a 10-second animation. This is a view of Yosemite Valley 1984-2009.
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White areas were those that exhibited an overall stable spectral trajectory.
Areas exhibiting a stable spectral trajectory include forests, shrublands, grasslands, bare ground, and water.
Identifying areas of vegetation growth.
Identifying areas of substantial vegetation growth and areas which did not regrow vegetation after a disturbance event highlights areas of particular interest. Areas in green are those that showed signs of growth.
Events such as fires, floods, avalanches were identified.
Using a 25-year stack of satellite images provides the unique opportunity to identify low magnitude and multi-year disturbance events usually associated with insect outbreaks, forest mortality from drought or disease, and other slow processes.
2002 Wolf Fire was lightning caused and effectively managed for the benefit of the resource. Management of this fire demonstrated the best of wildland fire practices, cooperative efforts, and interpretive techniques.
Yosemite National Park fire personnel and Rangers also seized the opportunity with the Wolf Fire and the neighboring Lukens Fire to lead walks to the fires. Safety for the visitor's was the first priority. The purpose of the walks was to challenge visitor's perceptions about wildland fire and to demonstrate a dynamic forest process. These fires were both low-intensity fires and easily demonstrated how fire cleanses the forest of fuel loads that can lead to catastrophic fires and how fire benefits the forest ecosystem. Visitors were able to see that fire is not only the catastrophic fire that is showcased in the media. Visitor interest was high and the program was always full. (http://www.nps.gov/archive/yose/news/2002/fire1120.htm)